Rotten roof truss

[zdacosta]

I have a 2005 sunline solaris t267. I need the measurements for roof trusses and the height?

[JohnB]

Hi,

I am away from my files right now, but if no one answers, I can measure the trusses I have in my shop that will match your camper. It will be about two weeks from now.

I'll ask a few questions. I assume you have not yet opened the roof so that you could measure it yourself. Yes/no? Either way, I'll pass this along to try and help.

If the bad roof truss is at the back wall, you can create a solid one out of a 2 x 6, which is easier than building a truss. The trusses along the main roof get more complex as the AC ducts pass through the truss.

See here what I'm referring to:




The AC unit truss is also larger in width than along the main roof,


On the larger slide Sunline campers, which I have been a part of, there are up to 4 different-size rafters pending location.

Area 1. The majority of the main roof length uses the same size rafter. The width and height are the same on all these, including the back wall.

Area 2. The two rafters that support the AC unit are wider than the rafters in area 1. The height and length are the same.

Area 3. This is up front, where the roof tapers down to tie in the front wall. I have seen only one rafter, which is the same width as area 1 but can have a shorter height to create a tapered-down effect on the front wall.

See the pic; the first two actual trusses, starting with the lay flat as rafter 1, which is 2 x 3, differ in height from the 1st, the 2nd, and then the 3rd truss, which is the rest of the roof in height.


Area 4, I have seen this front taper done with rafters 1 and 2 at different heights. But I have also seen this done in only one rafter height change. The difference may be the floor plan and where the front crank-up vent is located. A front bedroom floor plan looks like the pic above, using two truss height sizes before the main truss height. A non-slide camper with a crank-up vent in different locations may only have one rafter at the front that changes height, possibly due to the area of the front vent.

What areas are your rafters rotted in?

I have also successfully repaired rotted rafter ends rather than replacing the entire rater. In this case, about 18 to 24" if the rafter ends by the wall was bad, so I repaired the bad end. If you're interested in this, I can explain it more. Here are a few pics of the process; more typing is needed if you want to reproduce this on how to glue in and screw in the repair to be strong enough.

Front rafter area






Rear wall area.










I am still looking for where to buy premade rafters to fit a Sunline. I have had no luck so far. If you have a source, please let us know. I had to build all the new truss rafters, as repair was not a good choice. The rot consumed 3/4 of the rafters. The first time making a truss rafter was a learning curve. You have to pre-bend, and stress relieve the top chord. While my first ones did work, I needed to perfect the wood bending process. If all goes well, I will make a steaming box to bend and stress-relieve the top chord this winter. I have a camper that needs several all-new rafters.

Hope this helps

John

[zdacosta]

Front bedroom rafters are rotten. Going down the front of the camper above the window is rotten. 50% of the wall studs are rotten. We aren’t by the camper so I can’t take any pictures. We are working from the inside. We can’t take the siding off. I can’t wait 2 weeks. I wish that I could. So on the wall the studs are 1 1/2”x 1 1/2”? Then you have the top wall plate, the luan & the rafters sandwiched together? Do u recall the size of the board for the first rafter? It looks like a 1x2? Would u say that the 2nd rafter is half the size of the main trusses? Hopefully later today I can get by the camper & take some pics? Do u know if the main trusses are standard size 94 1/2” with height being 4 1/2 in the middle? Thank u for any help that I can get?

[JohnB]

Hi,

It sounds like you're in a tough spot with a time crunch. Pictures help in these cases, as we can see what you're against and give better feedback. Post as many as you can when you get some. And if you can, using a ladder from the side, take a pic of the front roof to the front siding area. The more feedback you give us, the better we can understand what you see.

I will help as much as possible and be creative with suggestions. I understand your time crunch, but your approach to the repair can cause some issues that you may not know about yet.

I'm going off the words you typed, so this might be off base or not.

Originally Posted by zdacosta

Front bedroom rafters are rotten. Going down the front of the camper above the window is rotten. 50% of the wall studs are rotten.

If rotted studs are above the front window and rotted rafters, that points to the roof's front membrane to the siding seam molding, or a front corner molding has leaked.

The way the camper is made makes repairing that type of leak from the inside complex, making it almost impossible for it to be structurally sound when you are done. I'll try to explain why I'm saying this so you can understand what you will run into. I'm open-minded, and maybe you can think of a way around the issues. Then, use us as a sounding board to see if it can cover all the bases.

The first thing is the roof membrane itself. Sunline bonded 2-layer EPDM rubber to a thick, dense corrugate liner, which I believe is called Unicore in the industry. Sunline nick named it "bud board". When the budboard gets wet from a leak, it wicks water across the budboard, creating even more damage. The membrane assembly (rubber and budboard) is all one piece is placed over the top of the rafters. There is no roof decking above the rafters, and as such, you cannot walk on the roof without support plywood pieces in place, or you will damage the roof. See here

This is the EPDM rubber lifted from the budboard


The roof membrane make up pulled over the rafters.


This here is mild water damage, it was caught just in time before significant damage came. This is from a 2006 T-276 SR almost the same as your but the front bedroom is rotated to a walk around bed




Here is what heavy water damage does to the budboard and what is under it. This is from a 2004 T1950 rear wall leak. The same thing can happen at the front wall.


There is no structure left to the budboard, and it's ability to shed water or hold any kind of snow load.


This is what it looks like under the roof with the wet insulation removed




You have to repair the roof section or replace the entire roof. I have done both, depending on the situation. After we can see what your looks like, we can sort out how to repair it, in a local section repair, etc.

I'm unsure if you tore out the ceiling yet; if you have rotted rafters and wall studs, there has been a good amount of water seeping in over many years. The water keeps working itself down the wall until it reaches the black plastic membrane at the bottom under the floor we call Darco. The water can't get out as the membrane holds it in. You may also have lower front wall water damage and possibly the floor under the bed.

Next, let's examine the wall studs, the top wall plate, and how the rafters tie into the wall. This leads to your questions.

We aren’t by the camper so I can’t take any pictures. We are working from the inside. We can’t take the siding off. I can’t wait 2 weeks. I wish that I could. So on the wall the studs are 1 1/2”x 1 1/2”? Then you have the top wall plate, the luan & the rafters sandwiched together? Do u recall the size of the board for the first rafter? It looks like a 1x2? Would u say that the 2nd rafter is half the size of the main trusses? Hopefully later today I can get by the camper & take some pics? Do u know if the main trusses are standard size 94 1/2” with height being 4 1/2 in the middle? Thank u for any help that I can get?

The wall studs are 1 1/2" in depth into the wall by 1" wide. I create new wall studs with SPF lumber, starting with a nominal 2 x 12 and ripping the board in the table saw into 1" wide wall studs. The 2 x 12 is 1 1/2" thick.

Some lumber yards sell 2 x 2's, which are 1 1/2" x 1 1/2". They are a little wider than the 1" Sunline studs but will work as replacements without having to rip them out of standard construction lumber.

The walls, being 1 1/2" deep, have a top plate that is 1 1/2" deep/wide x 1" thick and is stapled on both sides to the wall studs. See here on making walls stud frames.
https://www.sunlineclub.com/forums/f...tml#post151109



Once the stud frame is done, the 1/2" luan wall board goes onto the stud frame. They glue and staple fine wire staple the wallboard to the wall studs as needed. That wallboard, which is bonded to the stud frame, creates structural rigidity to the stud frame, making a wall.
See here for the wallboard install using construction adhesive.
https://www.sunlineclub.com/forums/f...tml#post151227



Next comes the ceiling and rafters that sit on top of the wall plate. Here is a section being rebuilt. What we started with


You create a ceiling assembly with a 1" wide (thick) by 1 1/2" tall outer band board. The rafters are stapled to the outer band board on top and bottom.


See here for more rafter framing. https://www.sunlineclub.com/forums/f...tml#post151304

The ceiling board is then glued (construction adhesive) to the rafter frame and stapled as needed. The thing to note is how the rafter downforce loads rest on top of the wall plate.

See here for the test fit and ceiling board install.
https://www.sunlineclub.com/forums/f...tml#post151370

These 2 pics show how the rafter assembly sites on the wall top plate.




The wall top plate is 1 1/2" wide. The ceiling assembly has a 1" wide outer band board that sits on top of the wall plate. The rafters only touch the top wall plate by 1/2" on each end. All the roof load goes down into the wall by 1/2" overlap of the rafter onto the top wall plate.

While those pics are of a back wall, the front of your camper side walls are the same as how the rafters tie in.

This post is on a 2006 T264SR, in which the front roof section is built like yours. While this post installed an entirely new walk-on roof, we had to rebuild the front top section due to the top roof leaking to the front seam and corner molding. It can help show how the front is made.
https://www.sunlineclub.com/forums/f...avy-16834.html

This link will drop you into the front damage https://www.sunlineclub.com/forums/f...tml#post130815

The first rafter is nominally 2 x 3, lying flat. The actual dimensions are 1 1/2 x 2 1/2". The second and third rafters are different heights from the main roof to create the downward pitch to the front.


I cannot recall out of my head the exact wall-to-wall outside distance of the wall stud frame. I "think" it is 96". So, 96" - 1" ceiling band board - 1" ceiling band board = 94" for the rafter straight distance. But again, I cannot confirm that until about two weeks from now. You can measure the inside of the camper and back into it as there is only 1/2" rafter overlap on the wall top plate. But, if you measure inside, remember the wallboard is 1/8", so you have to account for 1/4" of the wallboard in the length equation. I'm unsure where you get the 94 1/2" as a standard rafter length.

I have a question: What prevents you from removing the front siding? If you remove rotted wall studs, how will you restaple the siding to the new wall stud sections you install? The siding is stapled to the studs from the outside in, which also creates stability in the wall structure.

Were you also thinking you would not lift the roof off partly to install new rafters? You have to address the deteriorated bud board; this happens from the top down when installing a thin or thick decking to glue the rubber to.

I know you are now swimming in details, but you will run into these issues if you try to repair this damage from only inside the camper.

I hope this helps. Ask for more clarification.

John

[JohnB]

I found this in one of my notes I sent to another Sunline friend on a 2004 T317SR roof rafter. Your 2005 camper would be made the same.

They wanted to use these 95" nominal lengths rafters to repair their 2004 T267SR camper and asked me to check if they would work. https://www.rvsurplusparts.net/truss.html

I measured the 2004 T317SR camper I had apart in my shop and came up with this. This was my response.

I have a camper in the shop now with the roof off (see the 3 attached pics) so I could check how the PLS rafters would fit; there is good news and bad news.

The PLS rafter is 1/2" longer than the Sunline; this is not a problem; the ends can be cut to fit.

The PLS rafter is made well, but the top chord ends do not taper entirely to the end of the roof. An added piece could fix this.

PLS rafter could be taken apart and reworked with added materials to fit in a Sunline

Problems:
The PLS rafter is 4 1/2" tall at the center, and the Sunline rafter is 4 1/8" tall at the center; if all the roof rafters were changed, then extra 3/8" high of the PLS rafter is not an issue. If you only need a few new complete rafters, the roof line will not work as there would be a 3/8" bump going from old to new.

There are spacers in the PLS rafter at very different locations than Sunline has spacers. Sunline runs the ceiling AC ducts through the open spaces, and the duct runs into the PLS supports. Changing the AC duct path and how the duct is made is complicated.

The PLS rafter width is 1 1/2". The Sunline rafter varies depending on the location; most are 2" wide, and the ones holding the AC unit are 2 1/2" wide. The PLS rafter width creates problems if there is a roof decking splice; two sheets of plywood make a joint on the rafter, and the rafters are not always straight. It is not impossible to splice two sheets of plywood on the PLS rafter, but it is something to work through.

The PLS rafter top and bottom chords are thicker than the Sunline top and bottom chords (parts), so the PLS rafter might be rated for more weight. The AC ducts must fit through the gap between the top and bottom chords.

Bottom line: The main rafters are 4 1/8" tall at the center, 2" wide, and 94" long. The AC support rafters are 4 1/8" tall at the center, 2 1/2" wide, and 94" long. The side support plates are glued and stapled in the right location to allow the AC ducts to pass through them. I do not have with me the short-height rafters up at the front taper down to the siding seam, but they are 2" wide x 94" long. If you want to, I can get those dimensions in about two weeks, just let me know if it would help.

Hope this helps

John